Process of making wool-like artificial fibers



Patented Dec. 8, 1936 UNITED STATES PATENT OFFICE PROCESS OF MAKING WOOL-LIKE ARTIFICIAL FIBERS No Drawing. Application June 14, 1935, Serial No. 26,698. In Germany June 26, 1934 3 Claims.

Our present invention relates to an improved process of making wool-like artificial fibers.

According to our application Serial No. 757,372 filed December 13, 1934, a spun material obtained 5 by using a viscose ripened below the usual ripeness corresponding with ammonium chloride number of 7 to 6 (Hottenroth number) is converted to a new species of wool-like artificial fibers by treating it according to our application Serial No. 705,474 filed January 5, 1934 in a wet condition with organic liquids capable of dissolving water until the treated fibers still contain the so called molecular water usually present in commercial brands.

The present invention relates to an improvement of said process in accordance with which the particular procedure of desulfurization and the use of corresponding after treatment baths can be avoided. The present improved process comprises carrying out a treatment with the said 20 organic liquids capable of dissolving water in the presence of a volatile base. Advantageously the fibrous material may be treated in a plurality of baths of increasing strength as regards the said organic liquids and small quantities for instance 25 of ammonia may be added to the first bath of the lowest strength.

By the present combination of desulfurization and drying processes the whole procedure of manufacture is substantially simplified and the re- 30 action products are formed by a particularly economic method.

As an example a. suitable viscose material is washed with water and the excess of adherent water is removed by squeezing or centrifuging.

35 Then the material is immediately subjected to the treatment with ethyl alcohol. The first bath contains an alcohol of 35% strength, to which 1 to 10% of ammonia have been added and without any other intermediate treatment the material is manipulatedin further baths of an increasing strength of alcohol but free from ammonia. After passing through the last bath consisting for example of an alcohol of 92% strength, the adherent solvent is removed by squeezing or centrifuging and the residual alcohol is recovered in the known manner.

Advantageously the baths are combined together by overflow apparatus so that continuously the alcohol runs through all of the baths in counter-current to the fibrous material thereby showing a decreasing concentration and to the last bath containing the alcohol in the most dilute state, to which the material enters at first, ammonia is added.

We claim:

1. An improved process of making wool-like artificial fibers which comprises treating moist viscose material which has not been desulfurized with an organic liquid capable of dissolving water to which a little quantity of an ammonia base has been added.

2. An improved process of making wool-like artificial fibers which comprises treating moist viscose material which has not been desulfurized with alcohol to which a little quantity of an ammonia base has been added.

3. An improved process of making wool-like artificial fibers which comprises treating moist viscose material which has not been desulfurized with a plurality of baths containing alcohol of increasing strength, to the first of which of the lowest strength ammonia has been added.

ARTHUR VON WEINBERG. HANNS REIN. OTTO EISENHUT. 

